Air quality is a subject of major concern in a wide variety of industries. The control of particulate matter picked up and carried by air in enclosed working areas is of particular concern to the employer as well as to the employees working in a particulate laden environment. While there are a wide variety of pollutants which are indigenous to various industries, the present invention concerns itself primarily with what may be termed broadly as dust, but which is found to be prevalent in many agricultural processes such as cotton ginning, milling and the like. Apparatus for scrubbing and treating gasses has become virtually an industry unto itself. Devices such as huge air bags which filter exhaust air have been developed at high cost, but their size and cost of operation relative to the amount of exhaust gas they are capable of handling has made them prohibitive in some industries. Along with the dust problem is the problem of humidity which in many industries must be maintained at a pre-determined level not only for employee comfort, but to minimize static electricity and other problems attendant low-humidity air.
It has been recognized as far back as 1952 in the Johnstone et al. U.S. Pat. No. 2,604,185, that by injection of a fluid such as water into an air stream, a certain amount of particulate will absorb the moisture and the added weight will result in its being dispersed from the air stream. Others, such as Deane, in his U.S. Pat. No. 3,802,162 have recognized the value of centrifuging moisture laden particulate out of an air stream moving through the system. Apparatus such as that of Dean, however, use large volumes of water, in the neighborhood of 30 gallons per minute, and involve highly complex multi-stage, high energy demand systems which complicate and add to the expense of the system without increasing its efficiency.
The apparatus of the present invention makes use of many of the previously recognized physical principals in the development of a simple yet highly effective scrubbing device having a single scrubbing chamber, including a longitudinal opening for removal of scrubbed particulate from the chamber and further employing a means of interrupting flow from the chamber to bring about a final or second stage removal of particulate and excess moisture without any type of filtering device. As a result, through the use of controlled water injection and a unique means of generating moisture particles, the air passing through the chamber, which is relatively small in size, is effectively cleansed and humidified to provide optimum atmospheric and environmentally acceptable discharge air.